Pharmacokinetics and milk residues of cloxacillin in dairy cows after intramammary administration for dry cow therapy.

MARISA MARTÍNEZ; DANIEL BULDAIN; LAURA MARCHETTI; NORA MESTORINO; SANTIAGO GARCIA; FLORENCIA ALIVERTI; JUAN RODRÍGUEZ PÉRSICO; ANDREA BUCHAMER

Tucson, Arizona

Encuentro; NMC. National Mastitis Council. 57th Annual Meeting.; 2018

NMC. National Mastitis Council

Cloxacillin(CLOX) is known as an effective agent against penicillin-resistant and sensitive staphylococci (Staphylococcus aureus), the most prevalent Gram positive pathogen involved in persistent udder infections, which are targeted by the dry off therapy (Mestorino, 2012). SeveralCLOXbenzathine containing intramammary (IMM) suspensions are registered for use in cattle asantibiotics for IMMadministration at dry off. A new dry cow formulation (UbresanSEC, BiogenésisBagó) with CLOX as active ingredient has recently been approved in Argentina for treatment of subclinical mastitis at dry off and prevention of new bacterial infections during the dry period. This study has been performed in order to assess the pharmacokinetic features of CLOX in udder secretion of this product and to guarantee that the residual concentration of the active ingredient in milk from the following lactation does not exceed the maximum permitted residue level, when administered as a single IMM dose of 500 mg/quarter in Holstein cows at dryoff.